Embolitic material comprising calcium, intimal debris, pieces of an artheromatous plaque and/or thrombi, has the potential of migrating and causing distal tissue damage, for example, stroke and/or myocardial infarction. (See Topol, E. J. and Yadov, J. S., “Recognition of the Importance of Embolization in Athereosclerotic Vascular Disease”, Circulation 2000, 101:570.) Embolic material with the potential of distal tissue damage is often released during vascular interventional procedures, for example, stenting of an artheromatous region.
In response to the risk posed by released emboli during vascular intervention procedures, a mesh filter mounted on a specially adapted guidewire may be introduced into a blood vessel to strain released embolitic material from the circulation, thereby reducing the risk of distal tissue damage. To deploy such a mesh filter, a specially designed guidewire, for example having a built-in stop, may be placed in the blood vessel so that the stop is just distal to the target area. A collapsed filter is advanced along the guidewire until it is prevented from further advancement by the stop and opened so that it catches debris released from the target area.
Unfortunately, the specially designed guidewire is bulky and hard to manipulate due, in part, to the incorporated stop and accurate positioning of the filter is difficult once it has reached the guidewire stop. In addition, the use of a non-standard guidewire may require replacement or stocking of new catheterization sets.
Tsugita et al. in U.S. Pat. No. 6,361,971 B1 and US Applications 2002/0095174 and 2002/0183782, the disclosure of which is incorporated hereby in its entirety by reference, demonstrate filters and locking mechanisms.